I used to use Mango’s at XBA, but lately I have been using TA…
Go [here] (http://www.trueachievements.com/games.aspx#) and put in these filters:
Platform: All … or adjust if you don’t own a device
Release Status: Listed Only
Title Type: Games Only
Played Status: Games I’ve Not Played
Then, click on completion time to filter from quickest to longest. Unfortunately, there is no region filter so you’ll likely see a ton of NTSC-J games on the first page. However, there are also a ton of ID@Xbox. Depending on how much you’ve played thus far, you can go 3+ pages before you hit something that takes longer than 8 hours to complete.